JP4431875B2 - Method for producing flexible polyurethane foam molded article, flexible polyurethane foam molded article, and vehicle seat - Google Patents

Description

  The present invention relates to a method for producing a flexible polyurethane foam molded article, a flexible polyurethane foam molded article, and a vehicle seat.

Conventionally, it has been widely known that a flexible polyurethane foam used as an interior material for automobiles has a high hardness and a low wet heat compression property, and an improvement in the wet heat compression property decreases the hardness. There has been a demand for a method for solving the conflicting problem of improvement of the above (see Non-Patent Document 1: Macromolecules, 2001, 34, p.337-339).
The applicant of the present application has previously found that a flexible polyurethane foam containing a silicate has high hardness and excellent heat and heat resistance (see Japanese Patent Application No. 2003-445).

  Here, the water blended as a foaming agent in the polyurethane foam stock solution (the raw material of the flexible polyurethane foam) acts on the silicate, and when the silicate gels, the workability at the time of blending the raw materials and in the flexible polyurethane foam The fine dispersion state of the silicate will be impaired. Therefore, in the above Japanese Patent Application No. 2003-445, a method of separately preparing a mixed solution of water and an isocyanate component and a mixed solution of a silicate and a polyol component and mixing them immediately before foaming is adopted. ing.

However, as long as it goes through such a blending process, there is an upper limit to the blending amount of silicate as a range where a finely dispersed state of silicate can be realized. The effect of improving the hardness of polyurethane foam and the effect of improving heat-and-heat compressibility were also limited.
A new flexible polyurethane foam molded article that can finely disperse silicate in the formed flexible polyurethane foam even when a higher proportion of silicate is blended in the polyurethane foam stock solution. Development of a manufacturing method has been desired.

Ruijian Xu and three others, Macromolecules, 2001, 34, p. 337-339

  The present invention has been made in view of the above circumstances, and has a high hardness, excellent wet heat compression resistance, and improved various other properties, and a method for producing the same, and a method for producing the same, and the flexible polyurethane foam It aims at providing the vehicle seat which uses a molded object.

As a result of intensive studies to achieve the above object, the present inventor has (A) a polyisocyanate for supplying an isocyanate group, (B) a polyol for supplying a hydroxyl group, (C) a layered silicate (hereinafter simply referred to as “ polyisocyanate”). The expression “silicate” may be used, but in the present invention, “layered silicate” is indicated) , and (D) a polyurethane foam stock solution containing water is foamed to form a molded body. obtained in process for producing a flexible polyurethane foam moldings, wherein (B) after the and components and component (D) were combined mixing, by preparing a polyol composition by mixing the component (C), silicate It has been found that the tendency of the salt to gel can be suppressed. As a result, even when silicate is blended at a higher ratio, it is possible to realize a finely dispersed state, and it is possible to realize a flexible polyurethane foam molded article having improved various characteristics compared to conventional products. As a result, the present invention has been made.

That is, the present invention provides the following method for producing a flexible polyurethane foam molded article, a flexible polyurethane foam molded article, and a vehicle seat.
Claim 1:
Each component of the following (A)-(D),
(A) a polyisocyanate supplying an isocyanate group,
(B) a polyol for supplying hydroxyl groups,
(C) layered silicate,
(D) water,
A foamed polyurethane foam stock solution in a mold to obtain a molded product, the step of mixing the component (B) and the component (D), Mixing the component (C) with the obtained mixture to prepare a polyol composition, and mixing the polyol composition with the component (A) to prepare a polyurethane foam stock solution. A method for producing a flexible polyurethane foam molded article.
Claim 2:
Furthermore, the following components (E) and (F)
(E) catalyst,
(F) foam stabilizer,
A foamed polyurethane foam stock solution in a mold to obtain a molded product, the step of mixing the component (B) and the component (D), The step of mixing the component (E) and the component (F) in the obtained mixture, then mixing the component (C) to prepare a polyol composition, and mixing the polyol composition and the component (A) And a step of preparing a polyurethane foam stock solution. The method for producing a flexible polyurethane foam molded article according to claim 1.
Claim 3 :
The manufacturing method of the flexible polyurethane foaming molding of Claim 1 or 2 with which the said (C) component is mix | blended 0.1-30 mass parts with respect to 100 mass parts of said (B) component.
Claim 4 :
4. The flexible polyurethane foam molded article according to claim 1 , wherein a viscosity of a polyol composition comprising each component excluding the component (A) in the polyurethane foam stock solution is 5000 mPa · s or less at a liquid temperature of 25 ° C. 5. Manufacturing method.
Claim 5 :
The soft body according to any one of claims 1 to 4 , wherein the molded body obtained by foaming the polyurethane foaming stock solution has a wet heat compression residual strain (%) measured in accordance with JIS K 6400: 2004 of 15% or less. A method for producing a polyurethane foam molded article.
Claim 6 :
The flexible polyurethane foam according to any one of claims 1 to 5 , wherein the molded product obtained by foaming the polyurethane foam stock solution has a resonance frequency (Hz) measured in accordance with JASO B 407 of 5 Hz or less. Manufacturing method of a molded object.
According to claim 7:
The method for producing a flexible polyurethane foam molded article according to any one of claims 1 to 6 , wherein a reaction force ratio of a molded article obtained by foaming the polyurethane foam stock solution is 30 or more.
Claim 8:
Flexible polyurethane foam molded body obtained by the production method according to any one of claims 1 to 7.
Claim 9 :
A vehicle seat pad comprising the flexible polyurethane foam molded article according to claim 8 .

  According to the present invention, it is possible to realize a flexible polyurethane foam molded article having not only excellent hardness and heat resistance as compared with conventional products but also improved various characteristics. The flexible polyurethane foam molded article obtained by the present invention is particularly suitable as a vehicle seat material.

The present invention will be described in further detail below.
The method for producing a flexible polyurethane foam molded article of the present invention includes the following components (A) to (D):
(A) a polyisocyanate supplying an isocyanate group,
(B) a polyol for supplying hydroxyl groups,
(C) layered silicate,
(D) water,
The polyurethane foam stock solution containing a process for producing a flexible polyurethane foam moldings to obtain a molded product by foaming in a mold, wherein (B) the component and the (D) that match mixed and component steps, the A step of preparing a polyol composition by mixing the component (C) with the mixture obtained in the step, and a step of preparing a polyurethane foam stock solution by mixing the polyol composition and the component (A). A process for producing a flexible polyurethane foam molded article, preferably, the following components (E) and (F):
(E) catalyst,
(F) foam stabilizer,
The polyurethane foam stock solution containing a process for producing a flexible polyurethane foam moldings to obtain a molded product by foaming in a mold, wherein (B) the component and the (D) that match mixed and component steps, the The step of mixing the component (E) and the component (F) in the mixture obtained in the step, and then mixing the component (C) to prepare a polyol composition, the polyol composition and the component (A) And a step of preparing a polyurethane foam undiluted solution by mixing.

As the polyisocyanate supplying the isocyanate group (A), tolylene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI) is preferably used from the viewpoint of the molding density region.
Here, the TDI is not particularly limited, but is a mixture having a blending ratio of 2,4-TDI and 2,6-TDI of 80/20 to 50/50 (mass ratio). A mixture of 80/20 to 65/35 (mass ratio) is particularly preferable.
On the other hand, the MDI is not particularly limited, and can be used regardless of the molecular weight distribution. For example, pure MDI (4,4'-MDI), polymeric MDI, crude MDI Etc. can be used.
As such TDI and MDI, commercially available products can be used. As TDI, for example, TDI-80 (manufactured by Sumitomo Bayer Urethane Co., Ltd.), and as MDI, for example, 44V20 (manufactured by Sumitomo Bayer Urethane Co., Ltd.) MDI) can be used.

  When the above TDI and MDI are used in combination, the mixing ratio of the two is usually 20/80 to 80/20 (mass ratio) as the value of TDI / MDI (mass ratio), preferably 50/50 to 80/20 ( Mass ratio).

  The proportion of the component (A) in the polyurethane foam stock solution (when two or more isocyanates are used in combination, the total amount of the isocyanate in the polyurethane foam stock solution) is an isocyanate equivalent (soft polyurethane) as a guide. When the amount of active hydrogen (mol) in the foaming stock solution is 100, the equivalent (mole) ratio of isocyanate groups in the flexible polyurethane foam stock solution is usually 80 or more, preferably 95 or more, and the upper limit is usually 120 or less. , Preferably 115 or less. If the isocyanate equivalent is less than 80, poor stirring may occur, while if it exceeds 120, foam-down may occur.

Although it does not specifically limit as said (B) polyol which supplies a hydroxyl group in this invention, The mixture of polyether polyol or polyether polyol and polymer polyol can be used.
As the polyether polyol, a polyether polyol obtained by ring-opening polymerization of alkylene oxide is preferable from the viewpoint of reactivity. Examples of such alkylene oxides include propylene oxide (PO) and ethylene oxide (EO). These may be used alone or in combination of two or more.

  Among these, from the viewpoint of raw material activity, the polyether polyol obtained by copolymerizing the PO and EO is preferably used as the polyether polyol. The blending ratio of PO and EO during copolymerization is usually 8/92 to 18/82 (molar ratio) as EO / PO (molar ratio), preferably 13/87 to 15/85 (molar ratio). is there. When EO / PO (molar ratio) is out of the above range, it may be difficult to produce a polyether polyol.

  Further, the number of hydroxyl groups contained in one molecule of the polyether polyol is usually 2 to 4, particularly preferably 3. If the number of hydroxyl groups is too large, the raw material viscosity may increase, and if it is too small, the physical properties may decrease.

  As the polyether polyol, it is preferable to use one having a low degree of unsaturation. More specifically, a polyether polyol having an unsaturation degree of usually 0.07 meq / g or less is suitable. If the degree of unsaturation in the polyether polyol exceeds 0.07 meq / g, the durability and hardness of the flexible polyurethane foam molded article obtained by the production method of the present invention may be impaired. In the present invention, the “degree of unsaturation” refers to a method in which acetic acid released by acting mercuric acetate on unsaturated bonds in a sample is titrated with potassium hydroxide in accordance with JIS K 1557-1970. It means the measured total unsaturation (milli equivalent / g).

  The number average molecular weight of the polyether polyol is usually less than 8000, preferably 6000 or less, and the lower limit is usually 3000 or more, preferably 4000 or more. When the number average molecular weight of the polyether polyol is 8000 or more, the viscosity of the component (B) becomes too large, and the stirring efficiency of the polyurethane foam stock solution may be inferior. On the other hand, if the number average molecular weight of the polyether polyol is less than 3000, the resilience may be greatly reduced. In the present invention, the number average molecular weight is a value calculated as a polystyrene equivalent value by the GPC method.

  On the other hand, as the component (B) in the present invention, as a polymer polyol that may be used in combination with the polyether polyol, it is possible to use a general-purpose polymer polyol for a polyurethane foam molded article. More specifically, for example, a polymer component such as polyacrylonitrile or acrylonitrile-styrene copolymer is grafted to a polyether polyol made of polyalkylene oxide, preferably having a number average molecular weight of 3,000 to 8,000, preferably 4,000 to 7,000. Examples thereof include a copolymerized polyol. The alkylene oxide used as the raw material for the polyalkylene oxide preferably includes propylene oxide, and particularly preferably includes propylene oxide alone or includes both propylene oxide and ethylene oxide. Moreover, as a ratio of the above polymer components in the said polymer polyol, it is 25-50 mass% normally.

  When a polyether polyol or a mixture of a polyether polyol and a polymer polyol is used as the component (B) in the present invention, the blending ratio of both is (polyether polyol) / (polymer polyol) (mass ratio). Usually, it is 30 / 70-100 / 0, preferably 40 / 60-80 / 20. When the blending ratio of the two deviates from the above range, the physical properties of the obtained polyurethane foam molded article may be deteriorated or a reaction failure may occur.

As the component (B) in the present invention, the viscosity (the viscosity of the mixed polyol as a whole when the component (B) is mixed) is 5000 mPa · s or less at a liquid temperature of 25 ° C. The polyol is preferably used. The polyurethane foam stock solution in the present invention includes a polyisocyanate for supplying an isocyanate group and a polyol for supplying a hydroxyl group. By using a polyol having such a specific viscosity, the viscosity of the polyurethane foam stock solution is increased. Since the speed can be suppressed and the stirring efficiency is increased, and the isocyanate group and the hydroxyl group can react more uniformly, not only the generation efficiency of the generated gas is increased as compared with the conventional case. The generated gas is also generated uniformly in the polyurethane foam stock solution, and a lightweight and homogeneous polyurethane foam molded article can be obtained.
In the present invention, “viscosity” means the viscosity measured using a capillary viscometer at a liquid temperature of 25 ° C. in accordance with JIS Z 8803-1991.

  More specifically, the viscosity of the component (B) at a liquid temperature of 25 ° C. is usually 5000 mPa · s or less, preferably 1800 mPa · s or less, and the lower limit is usually 500 mPa · s or more, preferably 800 mPa · s or more. When the viscosity of the polyol is too large, the stirring efficiency of the polyurethane foam stock solution is lowered, and the object of the present invention may not be achieved. On the other hand, when the viscosity of the polyol is too small, the impact resilience is low and the wet heat compression residual strain characteristic may be deteriorated.

Examples of the (C) layered silicate in the present invention include, for example, a nesosilicate containing one silicon atom in a unit skeleton, a solosilicate containing several, an isosilicate containing a large number of silicon atoms, and a ferrosilicate. Specific examples include smectite clay minerals such as montmorillonite, saponite, hectorite, beidellite, stevensite, and nontronite, verculite, halloysite, and mica. These may be natural products or artificial synthetic products. These may be used alone or in combination of two or more.
In the present invention, the presence or absence of swellability of these silicates is not particularly limited, but from the viewpoint of dispersibility in the polyol component, swellable mica is preferable. From the viewpoint of the stability of the dispersed state in the polyol component, it is also preferable to use fluorinated mica in which the OH group on the mica surface is substituted with a fluorine atom.

As the silicate in the present invention, an organically treated silicate can be preferably used from the viewpoint of dispersibility in a polyol component.
Such an organic treatment method is not particularly limited, and a method of quaternary ammonium chlorination by ion exchange of a sodium ion as a counter ion of silicic acid, a chemical bond, an ion bond, etc. The method of introducing an organic group onto the surface of the silicate can be exemplified by the above, but from the viewpoint of dispersibility in the polyol, the silicate can be converted to 4 by exchanging sodium ions as counter ions of silicic acid. A method of quaternary ammonium chloride is preferred.

  Examples of the organic onium ion include organic ammonium such as hexyl ammonium ion, octyl ammonium ion, 2-ethylhexyl ammonium ion, dodecyl (lauryl) ammonium ion, octadecyl (stearyl) ammonium ion, dioctyl dimethyl ammonium ion, and distearyl dimethyl ammonium ion. Ions; organic pyridinium ions such as alkylbipyridinium ions, but are not limited thereto. Among these, organic ammonium ions are preferable from the viewpoint of stability in the polyol component. These are preferably quaternary ammonium ions, but may be protonated primary, secondary, or tertiary amines.

  Moreover, as said organic ammonium ion, the thing whose organic group couple | bonded with a nitrogen atom is an alkyl group and / or a hydroxyalkyl group is preferable, and especially the di (hydroxyalkyl) dialkyl ammonium ion is preferable. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. On the other hand, the hydroxyalkyl group may be one having one OH group or two or more OH groups, and may be a terminal carbon atom such as a hydroxymethyl group, a 1-hydroxyethyl group, or a 1-hydroxypropyl group. Having an OH group bonded to, having a OH group bonded to a carbon atom in the middle of the carbon chain such as 2-hydroxy-n-propyl group and 2-hydroxy-n-butyl group, 1,3-dihydroxy-n -What has an OH group couple | bonded with the carbon atom of the terminal and the carbon chain like a butyl group etc. are mentioned. Among these, from the viewpoint of the strength of the produced flexible polyurethane foam, those having an OH group at the terminal are preferable. In addition, as an organic group couple | bonded with a nitrogen atom, you may have an ester bond, a urethane bond, etc. in the middle of carbon chains, such as an alkyl group and a hydroxyalkyl group.

  Commercially available products may be used as such silicates in the present invention, for example, organic mica such as Somasif MEE, Somasif ME-100, Somasif MAE, Somasif MTE (all manufactured by Coop Chemical Co., Ltd.). Can be mentioned.

  Although it does not specifically limit as a compounding quantity of the silicate in this invention, Usually 0.1 mass part or more with respect to 100 mass parts of polyol of the said (B) component, Preferably it is 1.0 mass part or more. The upper limit is usually 30 parts by mass or less, preferably 5 parts by mass or less. When the amount is less than 0.1 parts by mass, improvement in moisture heat compressibility and hardness may hardly be exhibited. On the other hand, when the amount exceeds 30 parts by mass, the polyol component becomes highly viscous and the mixture cannot be made uniform. In some cases, the organically treated inorganic filler cannot be uniformly dispersed in the urethane foam.

The polyurethane foam stock solution in the present invention contains (D) water. Since water reacts with polyisocyanate to generate carbon dioxide, it can be used as a foaming agent in the present invention, and is also preferably used from the viewpoint of reducing environmental burdens and manufacturing costs.
The blending amount of (D) water in the polyurethane foam stock solution is usually 1 to 7 parts by mass, preferably 2 to 5 parts by mass with respect to 100 parts by mass of the polyol of the component (B). If the blending amount of the component (D) is out of the above range, the resulting flexible polyurethane foam molded article may be inferior in the thermal compression residual strain characteristics.

The polyurethane foam stock solution in the present invention preferably further contains (E) a catalyst and (F) a foam stabilizer. Each of these components can also contribute to shortening the production cycle time of the flexible polyurethane foam molded article.
As the catalyst (E), those commonly used for polyurethane foam can be used, and are not particularly limited. Examples thereof include amine catalysts such as triethylenediamine and diethanolamine. As a compounding quantity of the (E) catalyst in a polyurethane foam undiluted | stock solution, it is 0.3-2 mass parts normally with respect to 100 mass parts of polyols of the said (B) component.
A commercial item can be used as such (E) component, For example, a triethylenediamine (made by Kao Co., Ltd.), diethanolamine (made by Nippon Shokubai Co., Ltd.), etc. can be mentioned.

  As the foam stabilizer (F), general-purpose foaming agents for flexible polyurethane foamed molded articles can be used. For example, silicone foam stabilizers such as various siloxane-polyether block copolymers can be used. it can. A commercial item can be used as such a foam stabilizer, For example, L5309 (Nihon Unicar Co., Ltd. product), SRX274C (Toray Dow Corning Silicone Co., Ltd. product) etc. can be used. In addition, as a compounding quantity of the foam stabilizer in the said polyurethane foam undiluted | stock solution, it is 0.3-2 mass parts normally with respect to 100 mass parts of polyols of the said (B) component.

  In the present invention, the viscosity at a liquid temperature of 25 ° C. of the mixture (polyol composition) composed of the remaining components obtained by removing the component (A) from the polyurethane foam stock solution is usually 5000 mPa · s or less, preferably 1800 mPa · s or less. The lower limit is usually 500 mPa · s or more, preferably 800 mPa · s or more. When the viscosity of the polyol composition is too large, the stirring efficiency of the polyurethane foam stock solution is lowered, and foaming is uneven and insufficient, and a desired polyurethane foam molded article may not be obtained. On the other hand, if the viscosity of the polyol composition is too small, the impact resilience may be low and the wet heat compression residual strain characteristics may be poor.

The method of manufacturing flexible polyurethane foam molded product of the present invention, the (B) and component and the (D) that match mixed and component steps, polyols by mixing the component (C) to the mixture obtained in the step A method for producing a flexible polyurethane foam molded article comprising: a step of preparing a composition; and a step of mixing the polyol composition and the component (A) to prepare a polyurethane foam stock solution.
In the present invention, in the initial stage of preparing the polyurethane foam stock solution, the (B) polyol component supplying the hydroxyl group and the (D) water component are mixed , and then the (C) layered silicate component is mixed. It has been found that the silicate can be dispersed better in the polyurethane foam stock solution, and as a result, the hardness and wet heat compressibility of the resulting foamed molded product can be further improved. It is.

The component (B) and the component (D) and that the match mixing process, and, as the mixing conditions for further mixing said component (E) and (F) component, usually 100rpm as speed during agitation As mentioned above, Preferably it is 1500 rpm or more, and is 3000 rpm or less normally as an upper limit, Preferably it is 2500 rpm or less. The stirring time is usually 10 minutes or longer, preferably 15 minutes or longer, and the upper limit is usually 30 minutes or shorter, preferably 20 minutes or shorter.
On the other hand, the component (C) is mixed with a mixture obtained by mixing the component (B) and the component (D) ( including the case where the components (E) and (F) are mixed). The mixing conditions for preparing the polyol composition are usually 100 rpm or more, preferably 1500 rpm or more as the rotation speed during stirring, and usually 3000 rpm or less, preferably 2500 rpm or less as the upper limit. The stirring time is usually 10 minutes or longer, preferably 15 minutes or longer, and the upper limit is usually 30 minutes or shorter, preferably 20 minutes or shorter.

  In the present invention, normal conditions can be used as conditions for obtaining a molded product by foaming a polyurethane foam stock solution in a mold, and it may be foam-cured under normal pressure or foam-cured under reduced pressure. May be. The decompression method here includes, for example, a lower mold and an upper mold that forms a sealed cavity space between the lower mold by covering the open portion of the lower mold, and these upper and lower molds are detachable from each other. An example is a method in which a polyurethane foam stock solution is supplied into the cavity space of the disposed mold body and foamed and molded.

  In the production method of the present invention, the mold temperature during foam molding is usually 50 to 70 ° C. In addition, when employ | adopting a decompression construction method, as temperature of the polyurethane foam undiluted solution at the time of injecting the above-mentioned polyurethane foam undiluted solution in a cavity, it can be made into about normal temperature.

When the decompression method is employed in the production method of the present invention, the expansion ratio of the polyurethane foam stock solution is usually 10 times or more, preferably 20 times or more, and the upper limit is usually 40 times or less, preferably 30 times or less.
The amount of the polyurethane foam stock solution injected into the mold is usually 1/10 to 1/40 as the volume ratio of the polyurethane foam stock solution to the mold volume ((volume of the polyurethane foam stock solution) / (mold volume)). , Preferably 1/20 to 1/30.
In addition, as long as molding using a mold is performed, it is usually estimated that the polyurethane foam stock solution after foaming is larger than the mold volume, and the polyurethane foam stock solution is injected into the mold. The ratio of the volume of the subsequent polyurethane foam stock solution to the mold volume ((volume of the polyurethane foam stock solution after foaming) / (mold volume)) is usually 1/1 or higher, preferably 1.2 / 1 or higher, upper limit Is usually 1.5 / 1 or less, preferably 1.4 / 1 or less.

In the production method of the present invention, from the viewpoint of improving the reaction force ratio of the obtained polyurethane foam molded article, it is preferable to use a polyol component not containing a polymer polyol as the component (B).
Here, in the present invention, the “reaction force ratio” is measured using a measuring apparatus according to JIS K 6400: 2004, (50% compression reaction force at bottom) / (φ10 disk 5% reaction force at compression) ) Means the ratio value.
The reaction force ratio of the flexible polyurethane foam molded article obtained by the production method of the present invention is usually 30 or more, preferably 35 or more.

More specifically, the measurement method of the above “reaction force ratio” is a size including a circle having a diameter of 300 mm or more on a table having a large number of small holes having a diameter of 6 mm and a center distance of 19 mm in order to make the test piece air easily escape. First, using an Instron type compression load tester with an automatic recording device, first measure the thickness when 4.9 N is applied from the upper surface of the test piece with a circular pressure plate with a diameter of 10 mm. The first thickness. Next, after pushing a distance of 75% of the initial thickness of the φ10 circular pressure plate at a speed of 50 mm / min, the pressure plate is immediately raised at a speed of 50 mm / min and returned to the initial thickness. After standing for 1 minute, it is compressed again to the distance of 5% of the original thickness at the same speed, and it is allowed to stand still and the load after 20 seconds is read. This will be referred to as “φ10 disk 5% compression reaction force”. Further, a bottom-type pressure plate having a diameter of 200 mm was used as the pressure plate, and after measuring the initial thickness, a distance of 75% of the initial thickness was pushed in at a speed of 50 mm / min, and then immediately at a speed of 50 mm / min. Raise the pressure plate and return to the initial thickness. After standing for 1 minute, it is compressed again to the distance of 50% of the initial thickness at the same speed, and the load after 20 seconds is read after resting. This is referred to as “butt type 50% compression reaction force”.
The “reaction force ratio” in the present invention is a value obtained by dividing the “reaction force at the bottom 50% compression” thus obtained by the “reaction force at 5% compression at φ10 disk”. It is used as an index for evaluating the characteristics of the molded body. A larger reaction force ratio means that the surface of the polyurethane foam molded body is softer and softer, and at the same time, the hardness of the center of the polyurethane foam molded body is higher and has a firm feeling.

The density of the flexible polyurethane foam molded article obtained by the production method of the present invention is usually 70 kg / m ³ or less, preferably 60 kg / m ³ or less, more preferably 55 kg / m as the “apparent density” defined by JIS standards. ³ or less, more preferably 50 kg / m ³ or less.

  The hardness (25% hardness of the molded body skin part) measured in accordance with JIS K 6400: 2004 of the flexible polyurethane foam molded article obtained by the production method of the present invention is usually 5 kgf or more, preferably 10 kgf or more. Usually, it is 40 kgf or less, more preferably 30 kgf or less.

  Further, the wet heat compression residual strain (%) measured in accordance with JIS K 6400: 2004 of the flexible polyurethane foam molded article obtained by the production method of the present invention is usually 15% or less, preferably 10% or less, more preferably. Is 8% or less, more preferably 6% or less.

  Furthermore, the resonance frequency (Hz) measured in accordance with JASO B 407 of the flexible polyurethane foam molded article obtained by the production method of the present invention is usually 5 Hz or less, preferably 4 Hz or less, more preferably 3.5 Hz or less, More preferably, it is 3.3 Hz or less.

Low-density soft polyurethane that can realize the above-mentioned flexible polyurethane foam molded article by the production method of the present invention, and can be suitably used for applications such as urethane foam with high sound absorption, sheets and pad materials that can cope with thinning A foamed molded product can be obtained.
In particular, when a flexible polyurethane foam intended for use for a vehicle seat pad is to be manufactured, it is desired that the resonance frequency be smaller. The method for producing a flexible polyurethane foam molded article of the present invention is a production method capable of setting a large amount of silicate to be blended, and is particularly suitable as a method for producing a flexible polyurethane foam having a smaller resonance frequency.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Examples 1 to 3]
A polyurethane foam stock solution was prepared at the blending ratio shown in Table 1. In preparing the polyurethane foam stock solution, first, a polyol and water are mixed and stirred for 20 minutes at 1800 rpm, then an amine catalyst, a silicone foam stabilizer, and a crosslinking agent are mixed and stirred for 10 minutes at 1800 rpm, and then the silica is mixed. The acid salt was gradually added while stirring at 1800 rpm, and after the addition was completed, the mixture was stirred at 1800 rpm for 30 minutes to obtain a polyol composition. This polyol composition and isocyanates 1 and 2 were mixed and stirred at 5000 to 7000 rpm for 5 to 10 seconds to obtain a polyurethane foam stock solution.
The obtained polyurethane foam stock solution was poured into a cavity of a mold (mold temperature 60 ° C., volume 20 L). The amount of polyurethane foam stock solution charged was 1.2 kg. Various physical properties of a flexible polyurethane foam molded article obtained by foam curing were evaluated. The results are also shown in Table 1.

[Example 4, Comparative Example 1]
A polyurethane foam stock solution was prepared at the blending ratio shown in Table 1. In preparing the polyurethane foam stock solution, first, polyol, water, amine catalyst, silicone-based foam stabilizer and cross-linking agent are mixed and stirred at 1800 rpm for 30 minutes, and then silicate is stirred at 1800 rpm as necessary. The polyol composition was obtained by gradually adding the mixture while stirring and stirring at 1800 rpm for 30 minutes. This polyol composition and isocyanates 1 and 2 were stirred at 5000 to 7000 rpm for 5 to 10 seconds to obtain a polyurethane foam stock solution.
The obtained polyurethane foam stock solution was poured into a cavity of a mold (mold temperature 60 ° C., volume 20 L). The amount of polyurethane foam stock solution charged was 1.2 kg. Various physical properties of a flexible polyurethane foam molded article obtained by foam curing were evaluated. The results are also shown in Table 1.

[Comparative Example 2]
A polyurethane foam stock solution was prepared at the blending ratio shown in Table 1. In preparing the polyurethane foam stock solution, a polyol composition was obtained by mixing polyol, water, silicate, amine catalyst, silicone-based foam stabilizer, and crosslinking agent and stirring at 1800 rpm for 10 minutes. This polyol composition and isocyanates 1 and 2 were mixed and stirred at 5000 to 7000 rpm for 5 to 10 seconds to obtain a polyurethane foam stock solution.
The obtained polyurethane foam stock solution was poured into a cavity of a mold (mold temperature 60 ° C., volume 20 L). The amount of polyurethane foam stock solution charged was 1.2 kg. Various physical properties of a flexible polyurethane foam molded article obtained by foam curing were evaluated. The results are also shown in Table 1.
[Comparative Example 3]
A polyurethane foam stock solution was prepared at the blending ratio shown in Table 1. In preparing the polyurethane foam stock solution, first, isocyanates 1 and 2 and water were mixed and stirred at 1000 rpm for 1 minute to obtain an isocyanate mixture. Next, a polyol, an amine catalyst, a silicone-based foam stabilizer, and organic mica were mixed and stirred at 1800 rpm for 30 minutes to obtain a polyol mixture. This isocyanate mixture and the polyol mixture were mixed and stirred at 5000 to 7000 rpm for 5 to 10 seconds to obtain a polyurethane foam stock solution.
The obtained polyurethane foam stock solution was poured into a cavity of a mold (mold temperature 60 ° C., volume 20 L). The amount of polyurethane foam stock solution charged was 1.2 kg. Various physical properties of a flexible polyurethane foam molded article obtained by foam curing were evaluated. The results are also shown in Table 1.

Polyether polyol number average molecular weight 5,000, functional group (OH group) number 3, EO 15%, PO 85% (charged mole). Unsaturation degree 0.065 meq / g. Viscosity 1000 mPa · s (liquid temperature 25 ° C.).
Silicate Somasif MEE (manufactured by Corp Chemical Co., Organic Mica)
Amine catalyst Dabco33LV (manufactured by Sankyo Air Products)
Silicone foam stabilizer SRX274C (manufactured by Toray Industries, Inc.)
Made of Asahi Glass as a cross-linking agent . Number average molecular weight 400, number of functional groups 4, EO 100% (charged mole)
Isocyanate 1
T-80 (Mitsui Takeda Chemical Co., Ltd.)
Isocyanate 2
44V20 (manufactured by Sumitomo Bayer Urethane Co., Ltd.)

Density (kg / m ³ )
The total density was measured by the method described in JIS K 6400: 2004. The total density refers to the “apparent density” defined by the JIS standard. In the present invention, the total density was measured using a rectangular parallelepiped foam sample with an epidermis skin.
25% hardness, 65% hardness (kgf)
The measurement was performed according to JIS K 6400: 2004.
In order to make it easy for air to escape from the test piece, the test piece was placed on a table with a number of small holes having a diameter of 6 mm and a center distance of 19 mm. Next, it was pressed from the upper surface of the test piece with a circular pressure plate having a diameter of 200 mm using an Instron type compression load tester having an automatic recording device. At this time, a test piece having a size including a circle having a diameter of 300 mm or more was used, and a test was performed by ILD (local compression).
The thickness when 4.9 N was applied as a preload was measured, and this was the initial thickness. Next, the circular pressure plate was pushed in at a distance of 75% of the initial thickness at a speed of 50 mm / min. Immediately after pressing, the pressure plate was raised at a speed of 50 mm / min and returned to the initial thickness. After standing for 1 minute, it was compressed again to the distance of 25% (or 65%) of the original thickness at the same speed, and the load after 20 seconds was read after being stopped. This was 25% (or 65%) hardness.
Humid heat compression residual strain (%)
The wet heat compression residual strain was measured by the compression residual strain measurement method described in JIS K 6400: 2004. However, in the measurement, the core part of the molded flexible foam was cut out by 50 × 50 × 25 mm and used as a test piece. The test piece was compressed to a thickness of 50%, sandwiched between parallel flat plates, and left under conditions of 50 ° C. and relative humidity of 95% for 22 hours. And after leaving for 22 hours, this test piece was taken out, 30 minutes later, its thickness was measured, compared with the value of the thickness before the test, the strain rate was measured, and this strain rate was defined as the wet heat compression residual strain.
Resonance frequency (Hz)
Measured according to JASO B 407. A 41 kg pressure plate was placed on the sample, and the frequency was vibrated to 1 Hz to 10 Hz. The frequency at which the maximum transmission rate was shown was the resonance frequency.

Comparative Example 1 is an example in which a polyurethane foam stock solution was prepared by mixing (B) component and (D) component and then mixing with isocyanate without blending silicate. By comparison with Example 3, it is clear that the wet heat compression residual strain value and the co-frequency value are improved by the silicate formulation.
Comparative Example 2 is an example in which a polyol composition was prepared by mixing polyol, water, silicate, amine catalyst, silicone-based foam stabilizer, and cross-linking agent at a time, and mixed with isocyanate to prepare a polyurethane foam stock solution. It is. In Comparative Example 3, a polyol composition is prepared by mixing a polyol, a silicate, an amine catalyst, a silicone-based foam stabilizer, and a crosslinking agent at once, and a mixture of isocyanate and water is blended to form a polyurethane foam. This is an example of preparing a stock solution. By comparing with Examples 1 and 4, the (B) component and the (D) component were mixed in advance, and then the silicate was mixed, and further the isocyanate was mixed, so that the wet heat compression residual strain value and the co-frequency value were further increased. It is clear that a flexible polyurethane foam having excellent resistance can be obtained.

[Example 5, Comparative Examples 4 and 5]
A polyurethane foam stock solution was prepared at a blending ratio shown in Table 2. In preparing the polyurethane foam stock solution, first, polyether polyol, water, amine catalyst, silicone-based foam stabilizer, and crosslinking agent are mixed and stirred at 1800 rpm for 30 minutes, and then the silicate is gradually stirred at 1800 rpm. After the addition and the completion of addition, a polyol composition was obtained by stirring at 1800 rpm for 30 minutes. This polyol composition and isocyanates 1 and 2 were mixed and stirred at 5000 to 7000 rpm for 5 to 10 seconds to obtain a polyurethane foam stock solution.
The obtained polyurethane foam stock solution was poured into a cavity of a mold (mold temperature 60 ° C., volume 20 L). The amount of polyurethane foam stock solution charged was 1.2 kg. Various physical properties of a flexible polyurethane foam molded article obtained by foam curing were evaluated. The results are shown in Table 2. Unless otherwise specified, the raw materials and the evaluation method are the same as in Table 1.

Polymer polyol base PPG number average molecular weight 5000, base PPG functional group number 3. A polymer polyol obtained by graft copolymerizing a polymer component of acrylonitrile-styrene copolymer with PPG (polypropylene glycol).
Crosslinking agent number average molecular weight 400, functional group (OH group) number 4, EO 100% (charged mole).

Dry heat compression residual strain (%)
The dry heat compression residual strain was measured by the method for measuring compression residual strain described in JIS K 6400: 2004. However, in the measurement, the core part of the molded flexible foam was cut out by 50 × 50 × 25 mm and used as a test piece. The test piece was compressed to a thickness of 50%, sandwiched between parallel flat plates, and left at 70 ° C. for 22 hours. And after leaving for 22 hours, this test piece was taken out, 30 minutes later, its thickness was measured, compared with the thickness value before the test, the strain rate was measured, and this strain rate was defined as dry heat compression set. .
Repeated compression thickness reduction rate (%)
It measured based on JISK6400: 2004.
Repeated compression hardness reduction rate (%)
It measured based on JISK6400: 2004.
Rebound resilience (%)
It measured based on JISK6400: 2004.

Comparative Examples 4 and 5 are examples using polymer polyols. By comparison with Example 5, the flexible polyurethane foam obtained without using the polymer polyol is excellent in the reaction force ratio, the surface of the polyurethane foam molding is soft and soft, and at the same time, the hardness of the center of the polyurethane foam molding is It is clear that a flexible polyurethane foam with a high and firm feel is obtained.

Claims (9)

Each component of the following (A)-(D),
(A) a polyisocyanate supplying an isocyanate group,
(B) a polyol for supplying hydroxyl groups,
(C) layered silicate,
(D) water,
A foamed polyurethane foam stock solution in a mold to obtain a molded product, the step of mixing the component (B) and the component (D), Mixing the component (C) with the obtained mixture to prepare a polyol composition, and mixing the polyol composition with the component (A) to prepare a polyurethane foam stock solution. A method for producing a flexible polyurethane foam molded article. Furthermore, the following components (E) and (F)
(E) catalyst,
(F) foam stabilizer,
A foamed polyurethane foam stock solution in a mold to obtain a molded product, the step of mixing the component (B) and the component (D), The step of mixing the component (E) and the component (F) in the obtained mixture, then mixing the component (C) to prepare a polyol composition, and mixing the polyol composition and the component (A) And a step of preparing a polyurethane foam stock solution. The method for producing a flexible polyurethane foam molded article according to claim 1. The manufacturing method of the flexible polyurethane foaming molding of Claim 1 or 2 with which the said (C) component is mix | blended 0.1-30 mass parts with respect to 100 mass parts of said (B) component. 4. The flexible polyurethane foam molded article according to claim 1 , wherein a viscosity of a polyol composition comprising each component excluding the component (A) in the polyurethane foam stock solution is 5000 mPa · s or less at a liquid temperature of 25 ° C. 5. Manufacturing method. The soft body according to any one of claims 1 to 4 , wherein the molded body obtained by foaming the polyurethane foaming stock solution has a wet heat compression residual strain (%) measured in accordance with JIS K 6400: 2004 of 15% or less. A method for producing a polyurethane foam molded article. The flexible polyurethane foam according to any one of claims 1 to 5 , wherein the molded product obtained by foaming the polyurethane foam stock solution has a resonance frequency (Hz) measured in accordance with JASO B 407 of 5 Hz or less. Manufacturing method of a molded object. The method for producing a flexible polyurethane foam molded article according to any one of claims 1 to 6 , wherein a reaction force ratio of a molded article obtained by foaming the polyurethane foam stock solution is 30 or more. Flexible polyurethane foam molded body obtained by the production method according to any one of claims 1 to 7. A vehicle seat pad comprising the flexible polyurethane foam molded article according to claim 8 .